Systems and methods for determining replacement fluid and plasma flow rates for red blood cell exchange procedures

摘要

Systems and methods for performing a red blood cell exchange procedure are disclosed. In one aspect, the flow rates of a replacement fluid (e.g., red blood cells from a healthy donor) and plasma being flowed to a blood source are calculated based on certain parameters of the procedure that are known, including the flow rate of blood being drawn from the source and the volume of replacement fluid to be used during the procedure. The replacement fluid flow rate and the plasma flow rate are calculated in a way that allows for simultaneous depletion of the supply of replacement fluid and achievement of another prescribed process parameter. The other prescribed process parameter depends on the nature of the procedure, namely whether the fluid volume and hematocrit of the source are to change by the end of the procedure or remain the same.

主权项

1. A blood processing system comprising:
a blood separation device configured to separate whole blood from a blood source into a first component including separated red blood cells and a second component including separated plasma; an inlet pump operable to convey whole blood from the blood source into the blood separation device at a prescribed rate Q3; a plasma pump operable to convey separated plasma from the blood separation device to the blood source at a plasma flow rate; a replacement fluid pump operable to convey a replacement fluid to the source at a replacement fluid flow rate; and a controller programmed to
calculate the plasma flow rate and the replacement fluid flow rate based at least in part on Q3 and a volume VR of replacement fluid to be flowed to the source,adjust the operation of the replacement fluid pump to achieve the calculated replacement fluid flow rate, andadjust the operation of the plasma pump to achieve the calculated plasma flow rate, wherein the plasma flow rate and the replacement fluid flow rate are calculated so as to simultaneously deplete the volume VR of replacement fluid and achieve one other prescribed process parameter, wherein the prescribed process parameter is one ofmaintaining a hematocrit and a fluid volume of the source at constant levels,maintaining the hematocrit of the source at a constant level while changing the fluid volume of the source from an initial level to a prescribed level,maintaining the fluid volume of the source at a constant level while changing the hematocrit of the source from an initial level to a prescribed level, andchanging the hematocrit and the fluid volume of the source from initial levels to prescribed levels.